The separation of wax and fibers from plants is used for many purposes, but mostly the wax that covers plants is separated from the remaining parts of the plant in order to use the remaining parts of the plant for different purposes, such as bedding material for animals, power generation, gasification, fermentation, ethanol extraction, production of structural components e.g. crop straw plates. In most of the situations the wax is separated from the remaining parts of the plant in order to improve the quality or efficiency of such productions.
U.S. Pat. No. 1,715,194 discloses an apparatus for separating the wax from Candelilla plants, where the plant material is first reduced in length in a crusher, whereafter it is introduced into a decorticating machine performing a combined sieving and beating process on the plant material. This Candelilla dewaxing machine is simple in structure but provides a relatively inefficient separation of wax.
In this relation CN patent application no. CN102431073A discloses a crop straw de-waxing machine, which comprises a case, a stirring device, a power device, a de-waxing agent supply device, a feed inlet and a discharge outlet. A rotating shaft which penetrates through the integral case is mounted on the case, a transmission wheel is mounted at one end of the rotating shaft and connected with the power device by a transmission component, the stirring device is mounted on the rotating shaft and consists of a rotary drum, a plurality of stirring paddles are uniformly distributed on the surface of the rotary drum, a de-waxing agent container is disposed above the case, and a liquid delivery pipe is arranged between the de-waxing agent container and the inside of the case. The de-waxing agent is added into the case via a de-waxing agent container and the power device drives the stirring device to sufficiently stir and de-wax straw fibers in the case. This crop straw dewaxing machine is simple in structure and provides a relatively high degree of separation of wax, but it requires a significant amount of de-waxing agent for the de-waxing process.
Commercially available plant waxes are not very common due to a shortage of economically attractive production methods and plant wax sources. Plant waxes have traditionally been extracted by use of organic solvents such as chloroform, benzene and hexane followed by solvent evaporation and purification. Recently, an extraction process using supercritical CO2 has been disclosed.
The jojoba plant (Simmondsia chinensis), which grows in the semi-arid regions of Mexico and the U.S.A., is unique in producing wax esters rather than triacylglycerols in its seeds, and it has become a significant crop.
The leaves of the carnauba palm, Copernicia cerifera that grows in Brazil, have a thick coating of wax (“carnauba wax”), which can be harvested from the dried leaves.
Other vegetable “waxes” such as bayberry or Japan wax are better described as “tallows” as they consist mainly of high melting triacylglycerols.
Plant waxes are highly valued alternatives to waxes coming from the petrochemical industry, and may be used as natural and “green” substitutes for the mineral oil-based waxes in all sorts of use, including in cosmetics, medical additives, lubricants, polishes, surface coatings (wood, leather, garment, etc.), inks, paints, garment, etc., and even for use in candlelight.
Today, the major part of commercial plant waxes come from the jojoba plant and carnauba palm, but the production is far from being able to cover the potential market. Thus, there is a need for new ways of produce plant waxes in high quantum and at a relatively low price.